EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue
==================================================================
BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:185 [inline]
BUG: KASAN: use-after-free in sk_dst_get include/net/sock.h:1772 [inline]
BUG: KASAN: use-after-free in pppol2tp_session_init+0x4b4/0x4d0 net/l2tp/l2tp_ppp.c:607
Read of size 8 at addr ffff88808feeb268 by task syz-executor.0/9893

CPU: 0 PID: 9893 Comm: syz-executor.0 Not tainted 4.14.287-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 __read_once_size include/linux/compiler.h:185 [inline]
 sk_dst_get include/net/sock.h:1772 [inline]
 pppol2tp_session_init+0x4b4/0x4d0 net/l2tp/l2tp_ppp.c:607
 pppol2tp_connect+0xd5c/0x13d0 net/l2tp/l2tp_ppp.c:781
 SYSC_connect net/socket.c:1655 [inline]
 SyS_connect+0x1f4/0x240 net/socket.c:1636
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f4aca508109
RSP: 002b:00007f4ac8e7d168 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f4aca61af60 RCX: 00007f4aca508109
RDX: 000000000000002e RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f4aca56205d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc2c8d7d7f R14: 00007f4ac8e7d300 R15: 0000000000022000

Allocated by task 9893:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552
 sk_prot_alloc+0x5f/0x290 net/core/sock.c:1478
 sk_alloc+0x36/0xcd0 net/core/sock.c:1538
 inet6_create net/ipv6/af_inet6.c:183 [inline]
 inet6_create+0x2df/0xe20 net/ipv6/af_inet6.c:110
 __sock_create+0x303/0x620 net/socket.c:1275
 sock_create net/socket.c:1315 [inline]
 SYSC_socket net/socket.c:1345 [inline]
 SyS_socket+0xd1/0x1b0 net/socket.c:1325
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 9905:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
 sk_prot_free net/core/sock.c:1519 [inline]
 __sk_destruct+0x442/0x760 net/core/sock.c:1600
 sk_destruct net/core/sock.c:1615 [inline]
 __sk_free+0xd9/0x2d0 net/core/sock.c:1623
 sk_free+0x2b/0x40 net/core/sock.c:1634
 sock_put include/net/sock.h:1664 [inline]
 sk_common_release+0x1c5/0x2c0 net/core/sock.c:3062
 inet_release+0xdf/0x1b0 net/ipv4/af_inet.c:425
 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:450
 __sock_release+0xcd/0x2b0 net/socket.c:602
 sock_close+0x15/0x20 net/socket.c:1139
 __fput+0x25f/0x7a0 fs/file_table.c:210
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

The buggy address belongs to the object at ffff88808feeb040
 which belongs to the cache UDPv6 of size 1728
The buggy address is located 552 bytes inside of
 1728-byte region [ffff88808feeb040, ffff88808feeb700)
The buggy address belongs to the page:
page:ffffea00023fbac0 count:1 mapcount:0 mapping:ffff88808feeb040 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff88808feeb040 0000000000000000 0000000100000002
raw: ffffea0002ad8920 ffff8880a5378048 ffff8880a5336640 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808feeb100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808feeb180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88808feeb200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff88808feeb280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808feeb300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================